RWE has set out plans to offer a system-stabilizing secondary reserve, also known as automatic frequency restoration reserve, for the German power grid via its Amrumbank West offshore wind farm.
The transmission system operator TenneT recently granted the necessary pre-qualification for a capacity of 60 MW.
The secondary reserve complements the primary and minute reserves to maintain the grid frequency at a stable 50 Hertz, preventing potential grid failures.
To participate in the secondary reserve auctions, a participant's bid power - in this case, the 60 MW reduction in wind farm capacity - must be able to be fully activated within five minutes.
Starting in the first quarter of 2025, RWE will market this secondary reserve through daily balancing energy auctions.
From then on, the offshore wind farm off the German North Sea coast will not only supply green electricity but will also actively contribute to the stability of the German power grid.
Located approximately 37 kilometres west of the North Frisian island of Amrum, the Amrumbank West wind farm has 80 turbines with a total capacity of 302 MW.
With the provision of balancing reserve from wind, the company is now entering a new area, as it already has experience in marketing and providing balancing reserve for grid stabilization from various types of assets by means of pumped storage, gas-fired power plants and, more recently, batteries.
Market participants are remunerated by the transmission system operator for the provision of secondary reserve as well as for the actual supply.
Aside from Amrumbank West, RWE Supply & Trading plans to qualify additional RWE wind and solar farms for the automatic frequency restoration reserve and will also provide this service for external clients, as the marketing of balancing power opens up additional sources of income for renewable energy plant operators.
Electricity production and consumption must always remain balanced to ensure the target grid frequency of 50 Hertz. When frequency fluctuations occur anywhere in the grid area, the respective transmission system operator calls in balancing power to counteract and then correct the imbalance.
The capacity required for this is auctioned daily by the transmission system operator.
